When it comes to getting a new pet dog, most experts agree you should adopt, not buy. But getting a rescue animal isn’t always as easy as it seems.

Some 85 million American families now own a pet – about seven in 10 families -- but many unwittingly get animals raised by mass breeders, sometimes called “puppy mills.” Consumer advocates say thousands of prospective pet owners fall victim to pet scams each year.

Last month, authorities in Iowa busted a “puppy-laundering ring.” Dogs from puppy mills were given to fake rescue groups that existed only on paper, then were sold to pet stores.

When you’re ready to find a new puppy, start your search at a licensed animal shelter. Don’t pay more than a reasonable adoption fee. Be skeptical if you’re offered purebred dogs – those usually come from breeders. And if you’re going to use a breeder, choose one that sells directly to the public.

“You’re bringing something into your home. You have to do the proper research,” says Larry Cohen, a Humane Society volunteer.

Beware of buying puppies online, especially if the seller promises to ship the dog to you.

“They will very often ask for additional money,” warns Melissa Companick, with the Better Business Bureau. “Whether it’s, ‘We’re shipping it, but it needs a special crate to fly on the plane,’ or, ‘You need some special insurance to make sure the pet is covered until it gets delivered to you,’ they’ll ask for hundreds of dollars more. But in reality, there is no animal.”